1. Field of the Invention
The present invention relates to a slider having a locking mechanism for use in a slide fastener, and more particularly to a slider for slide fastener with locking device, in which a sheet-like spring having a locking pawl is elastically deformed by raising or laying operation of its pull so as to engage the locking pawl with a fastener-element row, thereby activating locking function.
2. Description of the Related Art
Conventionally, a slide fastener is mounted to an opening of clothes of every kind, and the opening is opened or closed by separating or meshing its fastener-element rows by means of a sliding operation of a slider. Further, in order to protect the fastener-element rows from being separated without necessity, it has been known to use a slider having a locking device.
As a slider for slide fastener with locking device, for example, a slider shown in FIG. 11 has been known. The slider is comprised of a body 1xe2x80x2, a sheet-like spring 2xe2x80x2 and a pull 3xe2x80x2. In the body 1xe2x80x2, one-side ends of an upper wing plate and a lower wing plate, which are disposed in parallel, are connected by a guide post 7xe2x80x2 so as to form an element guide groove 13xe2x80x2 between the both wing plates. The aforementioned sheet-like spring 2xe2x80x2 is mounted on a top face of the upper wing plate and is provided at one end thereof with a locking pawl 25xe2x80x2, which is adapted to project into the element guide groove 13xe2x80x2 through a pawl hole formed in the upper wing plate while it is provided at the other end with a spring portion which is adapted to be fixed in an accommodation groove formed at a front face of the guide post 7xe2x80x2. Further, the pull 3xe2x80x2 is provided at one end thereof with a grip portion 38xe2x80x2 which can be gripped with fingers while it is provided at the other end with an axle having a cam 39xe2x80x2 disposed between the body 1xe2x80x2 and the sheet-like spring 2xe2x80x2.
Elastic force is always applied to the axle of the pull 3xe2x80x2, thereby making it possible to keep the pull 3xe2x80x2 laid. Further, when the pull 3xe2x80x2 is raised to rotate the axle, the axle deforms the sheet-like spring 2xe2x80x2 elastically and pushes it up, so that the locking pawl 25xe2x80x2 can be retracted from the element guide groove 13xe2x80x2.
Particularly, the above-described slider for the slide fastener having the locking device is mounted on a slide fastener sewed to trousers or skirt made of jeans.
Because the jeans fabric is hard and, mechanical impact is applied to the clothes so as to improve its flexibility, feeling to the touch or the like, in order to overcome such a problem that the clothes made of jeans fabric gives an uncomfortable feeling to a wearer as it is. For example, a so-called stone wash operation is carried out, in which a stone of an appropriate size is thrown into a rotation drum together with the clothes to which the aforementioned slide fastener is sewed and then the clothes is struck by the stone when the rotation drum is rotated, or in which the clothes is thrown into a rotation drum provided with a multiplicity of protrusions on an inner periphery thereof and then the clothes is struck by the protrusions in accordance with the rotation of the rotation drum.
After the aforementioned slide fastener is sewed onto clothes such as trousers and skirt, usually the pull 3xe2x80x2 is laid to the side of a front end of the body 1xe2x80x2 so that most part of the pull 3xe2x80x2 is protruded from the front end of the body 1xe2x80x2 as shown in FIG. 11. If mechanical impact is applied under this condition, a load is applied to the pull 3xe2x80x2 in a horizontal direction, namely a direction of pressing the pull 3xe2x80x2 toward the axle, or in a vertical direction, namely a direction of pressing down the grip portion 38xe2x80x2 of the pull 3xe2x80x2. Because at this time, the axle of the pull 3xe2x80x2 raises the locking pawl 25xe2x80x2 and at the same time the grip portion 38xe2x80x2 of the pull 3xe2x80x2 comes into contact with a bent portion 31xe2x80x2 of the sheet-like spring 2xe2x80x2 to press it excessively, plastic deformation is generated in the sheet-like spring 2xe2x80x2. If this state is induced, there occurs such a problem that even if it is intended to lay the pull 3xe2x80x2 to the side of the rear end of the body 1xe2x80x2 so as to activate the locking function, the locking function may not be activated because the locking pawl 25xe2x80x2 remains retreated from the element guide groove 13xe2x80x2. This problem can occur not only when the aforementioned stone wash operation is carried out, but also when clothes is washed with a washing machine with its pull being laid to the side of the front end of the body at home.
The present invention has been achieved in views of the above-described problems and a point of the present invention is to improve a sheet-like spring so as not to induce plastic deformation. According to a slider with a locking device of the present invention, plastic deformation of the sheet-like spring is prevented even if a load is applied to the pull in a horizontal direction or a vertical direction when the pull is laid to the side of a front end of a body of the. Thus, even if the slider is employed in jeans and the jeans is washed or handled roughly at home, the slider is free from being damaged so that it can exert its locking function accurately for a long period. Further, the present invention provides the slider for slide fastener with locking device with a simple structure and an excellent function.
Furthermore, in the slider with locking device having a locking mechanism in which the sheet-like spring comprises a bent portion bent in the same direction as a locking pawl, even if a load in the horizontal direction or in the vertical direction is applied to the pull when the pull is laid to the side of the front end of the body, no plastic deformation is induced in the bent portion of the sheet-like spring, so that it is capable of exerting its locking function accurately. Further, because the bent portion is capable of being elastically deformed sufficiently when the load is applied, it is possible to provide a slider for slide fastener with locking device in which its locking device is free from being damaged for a long period.
Still further, because in the slider with locking device, the pull is formed in an appropriate shape for protecting the sheet-like spring having the locking pawl from being plastically deformed, an excellent locking function can be exerted for a long period.
Still further, by restricting a range of a rising action of the sheet-like spring having the locking pawl, which is generated when the pull is laid to the side of the front end of the body and pressurized, the sheet-like spring can be prevented securely from being plastically deformed.